Pyridylphosphinate metal complexes: synthesis, structural characterisation and biological activity

Anticancer iridium(iii) cyclopentadienyl complexes

A comprehensive review of anticancer iridium(iii) cyclopentadienyl complexes, including a critical discussion of structure–activity relationships and mechanisms of action, is provided.

Anticancer potential of benzo[b]thiophene functionalized thiosemicarbazone ligands and their organoruthenium complexes

As novel promising anticancer candidates, the piano-stool type complexes of ruthenium, [RuCl(η6-p-cymene)(N,S-Ln)]PF6, K1-4, were synthesized from the reaction of the substituted benzo[b]thiophene based thiosemicarbazone ligands (L1-4) with [{RuCl(η6-p-cymene)}2(μ-Cl)2]. All complexes were fully characterized using elemental analysis, and spectroscopic methods such as FT-IR and 1H NMR. The molecular masses of the complexes were proved by MALDI-TOF analysis. Single crystal X-ray diffraction study was employed in the structural elucidation of complex K1 which shows a distorted octahedral geometry around the Ru(II) ion. Furthermore, spectroscopic methods revealed that in all complexes the ligands are coordinated to the metal center in neutral thione form via N, S donors. In this study, the effect of all ligands, complexes and commercial drugs with a different concentration on the viability of OVCAR-3, A2780 and OSE cells were compared. In this comparison, the cytotoxicity of ruthenium (II) complexes on two ovarian cancer cell lines (human A2780 and human OVCAR-3) was evaluated. For this purpose, the resazurin assay was performed. Based on our studies, complex K2 showed the highest toxicity against OVCAR-3 and A2780 cells. The cytotoxic effect of K2 was found to be higher than that of the commercial anticancer agents Oxalpin and Carbodex, 1.8-34.7-fold for OVCAR-3 cells and 1.9-11.8-fold for A2780 cells, respectively. These results provide insight into the potential of ruthenium (II) complexes as a cytotoxic agent for the treatment of ovarian cancer, particularly for primary tumors.

Dithiocarbamate-based novel anti-histaminic agents: synthesis, characterization, crystal structure and thermal study

A new N-(4-fluorobenzyl) N-(pyridin-2-ylmethyl) dithiocarbamate ligand (fbpm) having structural similarity to clinically approved antihistaminic drugs (viz. pheniramine, chlorpheniramine, and brompheniramine) and its four metal complexes [Co(fbpm)3] (1), [Ni(fbpm)2] (2), [Cu(fbpm)2] (3), and [Zn(fbpm)2] (4) were successfully synthesized and characterized by various techniques i.e. elemental analysis, FT-IR spectroscopy, HR-MS, NMR spectroscopy, and absorption and emission spectroscopy. Furthermore, complexes 1 and 2 were characterized by single crystal X-ray diffraction. Complex 1 adopts distorted octahedral geometry around the Co(III) center while complex 2 adopts distorted square planar geometry around the Zn(II) center. X-ray data also showed various weak intermolecular C-H⋯F and C-H⋯N hydrogen bonding interactions leading to supramolecular architectures in complexes 1 and 2. The thermal decomposition study of complexes 1-4 analyzed by TGA shows that they are thermally stable up to 150 °C and also gives strong evidence for the formation of respective metal sulfides at higher temperatures. The antihistaminic activity of the ligand (fbpm) and its complexes 1-4 was examined against clonidine and haloperidol-induced catalepsy in Swiss albino mice of either gender in an in vivo animal model. The result shows that these synthesized compounds have antihistaminic potential to inhibit clonidine-induced catalepsy and may be targeted for different allergic conditions. Complex 3 showed maximum reduction in clonidine-induced catalepsy after 180 minutes of treatment when compared with the induced control.

Catalyst- and solvent-free regiospecific SNHAr phosphinylation of pyridines with H-phosphinates mediated by benzoylphenylacetylene

Pyridines undergo a facile SNHAr phosphinylation with H-phosphinates under catalyst- and solvent-free conditions (50-55 °C) in the presence of benzoylphenylacetylene to afford 4-phosphinylpyridines in up to 68% yield. In this reaction, benzoylphenylacetylene activates the pyridine ring by the formation of a 1,3(4)-dipolar complex, deprotonates H-phosphinates to generate P-centered anions and finally acts as an oxidizer, being eliminated from an intermediate ion pair. Terminal electron-deficient acetylenes (methyl propiolate and benzoylacetylene) are inefficient as mediators in the above SNHAr process.

Water-soluble copper pyrithione complexes with cytotoxic and antibacterial activity

Copper Pyrithione, [Cu(PyS)₂] has shown excellent biological activity against cancer cells and bacterial cells, however, it has extremely low aqueous solubility, limiting its applicability. Herein, we report a series of PEG-substituted pyrithione copper(II) complexes with significantly increased aqueous solubility. While long PEG chains lead to a decrease in bioactivity, the addition of short PEG chains leads to improved aqueous solubility with retention of activity. One novel complex, [Cu(PyS1)₂], has particularly impressive anticancer activity, surpassing that of the parent complex.

Synthesis of Phosphorus(V)-Substituted Six-Membered N-Heterocycles: Recent Progress and Challenges

Heterocycles functionalized with pentavalent phosphorus are of great importance since they include a great variety of biologically active compounds and pharmaceuticals, advanced materials, and valuable reactive intermediates for organic synthesis. Significant progress in synthesis of P(O)R2-substituted six-membered heterocycles has been made in the past decade. This review covers the synthetic strategies towards aromatic monocyclic six-membered N-heterocycles, such as pyridines, pyridazines, pyrimidines, and pyrazines bearing phosphonates and phosphine oxides, which were reported from 2012 to 2022.

Indole-containing arene-ruthenium complexes with broad spectrum activity against antibiotic-resistant bacteria

•

A new family of indole-containing arene ruthenium organometallic compounds are active against several bacterial species and drug resistant strains

•

Bactericidal activity observed against various Gram negative, Gram positive and acid-fast bacteria, demonstrating broad-spectrum inhibitory activity

•

Compound series exhibits low toxicity against human cells

•

Shows considerable promise as next generation antibiotics

Antimicrobial resistant (AMR) bacteria are emerging and spreading globally, threatening our ability to treat common infectious diseases. The development of new classes of antibiotics able to kill or inhibit the growth of such AMR bacteria through novel mechanisms of action is therefore urgently needed. Here, a new family of indole-containing arene ruthenium organometallic compounds are screened against several bacterial species and drug resistant strains. The most active complex [(p-cym)Ru(O-cyclohexyl-1H-indole-2-carbothioate)Cl] (3) shows growth inhibition and bactericidal activity against different organisms (Acinetobacter baumannii, Mycobacterium abscessus, Mycobacterium tuberculosis, Staphylococcus aureus, Salmonella enterica serovar Typhi and Escherichia coli), demonstrating broad-spectrum inhibitory activity. Importantly, this compound series exhibits low toxicity against human cells. Owing to the novelty of the antibiotic family, their moderate cytotoxicity, and their inhibitory activity against Gram positive, Gram negative and acid-fast, antibiotic resistant microorganisms, this series shows significant promise for further development.

Education Priorities and What Matters to Those Considering Living Kidney Donation

INTRODUCTION

Although informed consent content elements are prescribed in detailed regulatory guidance, many live kidney donors describe feeling underprepared and under informed. The goal of this pilot study was to explore the educational components needed to support an informed decision-making process for living kidney donors.

METHODS/APPROACH

A qualitative description design was conducted with thematic analysis of 5 focus groups with 2 cohorts: living kidney donor candidates (n = 11) and living kidney donors (n = 8).

FINDINGS

The educational components needed to engage in an informed decision-making process were: 1) contingent upon, and motivated by, personal circumstances; 2) supported through explanation of risks and benefits; 3) enhanced by understanding the overall donation experience; and 4) personalized by talking to another donor.

DISCUSSION

Tailoring education to meet the needs for fully informed decision-making is essential. Current education requirements, as defined by regulatory bodies, remain challenging to transplant teams attempting to ensure fully informed consent of living kidney donor candidates. Information on the emotional, financial, and overall life impact is needed, along with acknowledgement of relational ties driving donor motivations and the hoped-for recipient outcomes. Discussion of care practices, and access to peer mentoring may further strengthen the informed decision-making process.

Synthesis, Characterisation and In Vitro Anticancer Activity of Catalytically Active Indole-Based Half-Sandwich Complexes

The synthesis, characterisation and evaluation of the in vitro cytotoxicity of four indole-based half-sandwich metal complexes towards two ovarian cancer cell lines (A2780 and A2780cisR) and one normal prostate cell line (PNT2) are presented herein. Although capable of inducing catalytic oxidation of NADH and able to reduce NAD+ with high turnover frequencies, in cells and in the presence of sodium formate, these complexes also strongly interact with biomolecules such as glutathione. This work highlights that efficient out-of-cells catalytic activity might lead to higher reactivity towards biomolecules, thus inhibiting the in-cells catalytic processes.

Ligand-centred redox activation of inert organoiridium anticancer catalysts

Organometallic complexes with novel activation mechanisms are attractive anticancer drug candidates. Here, we show that half-sandwich iodido cyclopentadienyl iridium(iii) azopyridine complexes exhibit potent antiproliferative activity towards cancer cells, in most cases more potent than cisplatin. Despite their inertness towards aquation, these iodido complexes can undergo redox activation by attack of the abundant intracellular tripeptide glutathione (GSH) on the chelated azopyridine ligand to generate paramagnetic intermediates, and hydroxyl radicals, together with thiolate-bridged dinuclear iridium complexes, and liberate reduced hydrazopyridine ligand. DFT calculations provided insight into the mechanism of this activation. GS- attack on the azo bond facilitates the substitution of iodide by GS-, and leads to formation of GSSG and superoxide if O2 is present as an electron-acceptor, in a largely exergonic pathway. Reactions of these iodido complexes with GSH generate Ir-SG complexes, which are catalysts for GSH oxidation. The complexes promoted elevated levels of reactive oxygen species (ROS) in human lung cancer cells. This remarkable ligand-centred activation mechanism coupled to redox reactions adds a new dimension to the design of organoiridium anticancer prodrugs.

Use of a fluorinated probe to quantitatively monitor amino acid binding preferences of ruthenium(ii) arene complexes

Speciation of Ru(ii) arene complexes in mixtures of amino acids with coordinating sidechains is easily resolved by ¹⁹F NMR.

Ruthenium(ii) p-cymene complexes of a benzimidazole-based ligand capable of VEGFR2 inhibition: hydrolysis, reactivity and cytotoxicity studies

Ru(ii)-p-Cymene complexes of a bispyrazole-benzimidazole ligand inhibit vascular endothelial growth factor 2, reduce the cellular glutathione pool and inhibit cell migration.